The present invention relates to improvements in impact devices and particularly although not exclusively to impact hammers and like devices such as needle guns.
Needle guns generally comprise a number of hardened steel rods or "needles", tapered at one end and retainably mounted in a housing with the tapered or pointed ends extending outwardly. The retained ends of the needles are subjected to a "hammering" action generally by a rotating hammer or anvil device.
Needle guns and impact chisels may be used for a variety of purposes including removal of rust, dirt, paint or other coatings from surfaces prior to painting or other treatment. In addition, welding slag is readily removable from welded surfaces by the use of a needle gun or impact chisel. Needle guns have been found to be particularly suitable for roughening the surface of cured concrete where reconcreting is required.
Prior art impacting devices such as needle guns, impact hammers and impact chisels have generally suffered the disadvantages of being heavy and cumbersome in size and in operation, subject to considerable vibration. In addition, prior art impact devices have not been particularly efficient in their operation, especially when operating on uneven surfaces.